LIFE IN THE OCEAN. 499 



drawn from the German Ocean as from 100,000,000 to 150,000,000 

 marks, and, according- to British statistics, 11 pounds (5 kilos) of fish 

 are worth 1 mark (23.82 cents, or 2|- cents per pound). Consequently 

 the total catch of the German Ocean would be from 1,100,000,000 to 

 1,650,000,000 pounds, or from 8 to 12 pounds per acre, worth 17i to 

 26i cents.' 



This production is ver}- low, as compared with that of fish ponds. 

 In the latter the catch may give some idea of the production, but at 

 sea the fishermen only keep such fish as are profitable and can gener- 

 ally only take a part of the fish. The real production of the German 

 Ocean is, therefore, quite unknown. It is true that in a fish pond or 

 field the greater part of the parasites can be destroyed, while in the 

 sea we can not prevent the concurrence of creatures which, though 

 they are not worth catching and transporting (if they are of an}' value 

 at all), nevertheless draw their food from the general store. Still, I 

 think it highly improbable that the actual catch in the German Ocean 

 represents more than a small fraction of the real useful production. 

 We can onl}^ say that if the fishermen take all that could be taken the 

 proportionate production of the German Ocean is not a third of that 

 of the worst class of fish ponds. Besides, the best statistics of fish- 

 eries give but rough approximations, having rather a relative than an 

 absolute significance, so that it is quite likely that the catch is much 

 greater than the statistics show. In the case of the '" Hafen" of Stet- 

 tin, careful verification showed me that the actual catch was between 

 two and one-half and three times as great as the statistics showed. It 

 may be that the statistics of the German Ocean are nearer the truth, 

 yet it is certain that they do not include all the products of the sea. 

 For example, the enormous masses of seaweed that are thrown up 

 upon the shores by storms and are then utilized by farmers are not 

 taken into account. 



It would be desirable that each year all the fish should be taken from 

 the sea that it can naturally produce, and it would be interesting to 

 know how much this is, in order that we may take all that can be 

 taken without inconvenience to future production. 



Hensen has proposed to deduce the quantity of fish from the number 

 of eggs deposited in the spawning season. For the majority of species 

 of useful fish these eggs do not sink, but float, so that the motion of 

 the water, whether by currents or by wind, assure their being pretty 

 uniformly distributed. By making dippings with a fine net it is easy 

 to ascertain the number of eggs and larvte contained in the vertical 

 column of liquid of a given base, and by operating in this way over 

 an important body of water a great many times every day, so as to 

 correct contingent errors and possible variations, one will certainly 



1500,000,000 a 650,000,000 de kilos par hectare, ou 9 a 13.6 kilos, rcpr(5sentant uue 

 valeur de 1.8 a 2.7 marks. 



